I can't say you're wrong Stoney. Maybe I'm not seeing tip stall as an issue because it occurs so close to departure. It seems like the down aileron will increase the lift on the wing resisting the torquewise rotation and if the opposite wing is losing roll authority first you can just reduce the angle on the still effective aileron. It seems like the roll occurs at departure and not from reduced roll authority from tip stall. Am I missing something?
Two components are at work here: stall and reduced aileron effectiveness. Once a wing tip is stalled, the lift it produces is dramatically reduced, resulting in a destabilizing roll moment. Second, the reduced or interrupted airflow over the aileron reduces its ability to counteract destabilizing moments in the roll axis. It would require some fairly complex analysis to show this graphically, especially since there is a dynamic change in both the resulting lift distribution of the wing as this occurs, but the overall effect is that not only does the plane become destabilized in the roll axis, but the primary control surface that provides the stabilizing input experiences reduced effectiveness. A double-whammy, if you'll forgive the colloquialism.
Now, in some of the aircraft in-game, you can more easily manage this instability at the edge or even into the stall. Some of the aircraft in the game experience the tip-stall condition almost instantaneously with the rest of the wing stalling. Some planes begin to display it much earlier. The FW-190, given its inherent lower fixed roll stability, is more difficult to control. For example, one of the reasons I have a difficult time testing power off stalls in the FW190 is because of its instability approaching the stall. My speeds wander all over the place. Where I can get other planes to stall within 1 or 2 mph of each test, the FW-190 family gets so unstable at those speeds that the deviation between tests grows to 5-8 mph.
